Describe symbolism in The Murder of Roger Ackroyd by Agatha Christie

Poirot discovers Ursula's wedding ring in the goldfish pond. Her ring is symbolic of her relationship with her husband, their secret marriage, and ultimately, the exposure of his own secret..... his engagement to Flora Ackroyd. Her ring, which was a symbol of promise, becomes a symbol of betrayal..... and thus is thrown into the pond.